Characterizing precipitation variability in major Texas cities using radar precipitation estimates

In this study, high-resolution MPE (Multi-Sensor Precipitation Estimates) rainfall data are used to study the impact of the Urban Heat Island on the spatial variability of precipitation over five major Texas cities: San Antonio, Houston, Dallas, Ft Worth and El Paso from 1997 to 2013. Hourly MPE data at 4 x 4 km 2 resolution estimates are used to generate spatial maps characterizing the spatial distribution of seasonal precipitation for each city. The annual variability of seasonal precipitation was also examined. The results indicate significant differences in the average precipitation between the upwind control region and the urban-impacted region over the 16 years period from 1997 to 2013. For example, in San Antonio, the average precipitation in the urban-impacted region during the spring, summer, fall, and winter seasons was higher by up to 25.2%, 153%, 66.30% and 108.20% respectively, when compared to the urban center. In Houston the average precipitation in the urban-impacted region was higher by 30.10%, 82.10%, 34.04% and 47.07% during the spring, summer, fall and winter seasons than the urban center. The difference during the four seasons were 22.87%, 46.44%, 32.81%, 35.20% and 54.68%, 50.53%, 41.40% and 85.80% for Dallas and Fort Worth, respectively. In El Paso the average precipitation in the urban-impacted region during the spring, summer, fall and winter seasons was 288.85%, 121.37%, 84.21% and 171.72% respectively when compared to the urban center. The research has implications for policy makers, urban planners, water resource managers, and agriculture professionals who may use an understanding of urban precipitation distribution microclimate in the design of better drainage systems, planning of land use, or identification of optimal areas for agricultural activity.